JPH1043708A - Method and apparatus for thermal decomposition treatment of scrap car - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To eliminate the expensive process of shredding a scrapped car body and dispose of it, and to effectively recycle and collect scrapped cars. A scrap car body (4) obtained by removing valuable parts (3) from a scrap car (1) is steamed (5) to separate it into a pyrolysis gas, a pyrolysis oil (6), and a pyrolysis residue. Decomposition dioxin in decomposition residue, heavy metal 1
0 is collected in a vacuum exhaust system, and the scrap and the pyrolytic carbon 11 are repaired without the shredder process.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for pyrolyzing end-of-life vehicles, and more particularly to a technology for recycling end-of-life vehicles.

[0002]

2. Description of the Related Art Generally, an end-of-life vehicle (end-of-life vehicle) is an engine,
After scrapping the scrapped vehicle body from which valuable parts such as missions, batteries, tires, and liquids have been removed and cutting it, it is separated into irons, non-ferrous metals, and non-metals. Non-metals are called shredder dust, which had previously been landfilled in stable landfills, but due to the danger of heavy metal spills, a shift to managed landfills was required in April 1996. .

As a method for treating shredder dust, Japanese Patent Application Laid-Open Nos. 5-141641 and 7-80433 are known. JP-A-5-141641 discloses that shredder dust is incinerated by using molten steel or a high-temperature atmosphere in an electric furnace and using the dust as it is or as mixed dust as thermal energy.

[0004] Japanese Patent Application Laid-Open No. 7-80433 discloses a method in which waste car body is shredded after shredder treatment, and shredder dust is steamed and separated into gas, oil, moisture, and solid residual substances (hereinafter referred to as pyrolysis residues). Discloses a technique for carbonizing the entire amount or recovering it as gas and oil to reduce the amount of waste of hazardous substances.

[0005]

Since the shredding of a scrapped car body is a very expensive process, there is a demand for a technique for omitting the shredder and effectively recycling the scrapped body. In addition, the pyrolysis residue after steaming shredder dust contains a large amount of dioxins (harmful substances), and it was necessary to eliminate these dioxins in order to utilize this residue. Also, heavy metals had to be made harmless by evaporation.

[0006] The present invention proposes a completely new processing method in which the scrapped car body is no longer cut with a shredder, the scrapped car body is entirely steamed, and the pyrolysis residue is vacuum-processed at a high temperature.

[0007]

SUMMARY OF THE INVENTION According to the present invention, a waste vehicle body obtained by removing valuable parts from a waste vehicle is steamed and separated into pyrolysis gas, pyrolysis oil, waste vehicle body metal and pyrolysis residue. And the pyrolysis residue is introduced into a vacuum atmosphere at a high temperature and continuously heated, the decomposed matter and the evaporation in the pyrolysis residue are collected in a vacuum exhaust system, and after cooling,
An object of the present invention is to provide a method for thermally decomposing a scrap car, wherein copper wire is removed from the scrap metal. When the H ₂ gas is sealed during the heat treatment under vacuum, a reducing atmosphere can be maintained, and heavy metals are reduced, and metals can be easily collected in a vacuum exhaust system.

[0008] In the present invention, steaming is to heat a vehicle body with oxygen cut off as much as possible to generate a thermal decomposition product. The concrete means is a method of directly heating the vehicle body with a contact hot gas. A furnace or a furnace indirectly heated by radiation or the like can be used. In the case of direct heating, about 10% by volume of oxygen may remain in the furnace atmosphere.
Oxidation of metals and combustion of combustibles may occur slightly.

The reduction of dioxin emissions in the entire treatment process includes the following two steps: (a) combustion process, (b) heat recovery and exhaust gas cooling process, (c) exhaust gas treatment process, and (d) ash and residue detoxification process. There are measures in the process. In the process of detoxifying ash, heat dechlorination occurs by heat treatment in a reducing atmosphere, and this is known to be effective in reducing dioxin. Therefore, in the present invention, the waste car body that has been subjected to the steaming treatment is heated and held under reduced pressure to achieve further dechlorination.

[0010] An apparatus of the present invention for suitably carrying out the above-mentioned thermal decomposition treatment method comprises a heating furnace for housing and heating a waste car body, an N ₂ gas supply device disposed near the entrance and exit of the heating furnace, A thermal decomposition processing apparatus for a scrap car, comprising: a vacuum heating furnace provided downstream of the heating furnace; a vacuum pump; and a heavy metal recovery device. According to the present invention, by heating the pyrolysis residue under reduced pressure, heating is performed in a reducing atmosphere as compared with heating in the atmosphere, and dechlorination proceeds easily.

Next, the second invention of the present invention is capable of efficiently removing harmful substances and recovering heavy metals. The waste car body is charged into a closed furnace, and N ₂ gas is temporarily removed. After the inside of the furnace is replaced, the inside of the furnace is heated to 500 ° C. or more in an oxygen-free atmosphere while maintaining the internal furnace pressure at 765 Torr or more, and then heated to a predetermined temperature under a reduced pressure of 10 ⁻¹ to 10 ⁻³ Torr. A method of sequentially decomposing harmful substances in a pyrolysis residue and evaporating and separating heavy metals.

In this case, the heating after the N ₂ gas replacement is set to 500 ° C. or more and 650 ° C. or less in direct heating in which the combustion gas comes into contact with the object to be heated. In this second invention, dechlorination occurs when the waste car body subjected to the steaming treatment is heated and held,
When dioxin decreases and the temperature rises, heavy metals such as Hg and Cd first evaporate in a low temperature range under the same reduced pressure,
Zn and Pb are evaporated in a medium temperature range, Sn is evaporated in a high temperature range, and Cu and Cr are evaporated in a very high temperature range, and are discharged to a vacuum exhaust system.

In an oxygen-free atmosphere, the internal pressure of the closed furnace is set to 765 To.
While maintaining the temperature at rr or more, the waste vehicle is heated to 500 ° C. or more to thermally decompose and exhaust the gas in the furnace. If the temperature is lower than 500 ° C., thermal decomposition progresses slowly, so the temperature is set to 500 ° C. or higher. The upper limit is not limited in the case of indirect heating, but is limited to 650 ° C. in the case of direct heating. This limits the amount of metal oxides that exceed the permissible value due to oxidation, which makes it difficult to recover heavy metals and the like that have become oxides in subsequent steps by evaporation. For example, 700 ° C under air
In one hour, the scale, which is a restriction condition of the steel raw material used in the electric furnace, exceeds the limit of less than 5% of the surface layer. The furnace pressure is set at 765 Torr or more to prevent intrusion of the atmosphere from the viewpoint of safety, and is set to be higher than the atmospheric pressure.

Next, the decomposition of harmful substances and the evaporation and separation of heavy metals are performed under reduced pressure of 10 ^-1 to 10 ^-3 Torr. 10 ^-1 T
If the pressure is higher than orr, the evaporation temperature of heavy metals will not be sufficiently low, and it will be difficult to recover by evaporation. Even if the vacuum is higher than 10 ⁻³ Torr, the effect is saturated, so the lower limit is set. Under a high vacuum of 10 ^-1 to 10 ^-3 Torr, the evaporation temperature of heavy metals is as shown in Table 1. Table 1 shows the evaporation temperature of main metals at normal pressure (760 Torr) and 5 × 10 ^-2 Torr.

[0015]

[Table 1]

According to the present invention, by heating the pyrolysis residue under reduced pressure, (1) dioxin is heated under a reducing atmosphere as compared with heating at atmospheric pressure, and dechlorination proceeds easily. I do. (2) Heavy metals can be extracted and recovered in the form of separate heavy metals by placing a plurality of vacuum heating furnaces with different heating temperatures from a low-temperature furnace at medium, high, and ultra-high temperatures under the same reduced pressure. .

An apparatus for performing the second method includes:
A heating furnace for storing and heating the scrap car body, an N ₂ gas supply device disposed near the entrance and exit of the heating furnace, and a vacuum pump disposed downstream of the heating furnace and a vacuum pump for evaporating heavy metals under the atmosphere. It is preferable to use a thermal decomposition treatment apparatus for a scrap car, which is provided with compartment vacuum chambers each having a heating device for increasing the temperature to a required temperature, and each of the compartment vacuum chambers is provided with a heavy metal recovery device.

[0018]

FIG. 1 is a flow sheet according to an embodiment of the present invention. The end-of-life vehicle 1 is subjected to steaming through a process 2 of removing valuable parts 3 such as an engine, a mission, and a catalyst, dangerous substances such as tires, batteries, and liquids and pollutants.
The scrap car body 4 from which the valuable parts 3 have been removed separates pyrolysis gas, oil, and water 6 in the steaming process 5. The scrap car body is continuously sent to a vacuum processing step 9. Here, the decomposed dioxin and heavy metal 10 are recovered, and the non-evaporated metals and pyrolytic carbon are discharged. The pyrolysis gas, oil, and water 6 become a fuel 13 through a cleaning treatment step 12.

FIG. 2 is a plan view showing an embodiment of the apparatus used in this method. The scrap car body 21 is charged into the forehearth 22, and the vacuum pump 23 eliminates the atmosphere air in the furnace 22,
N ₂ gas is supplied through the pipe 28 and N _{2 is} replaced.
Next, the scrapped vehicle body is fed into the furnace 28, where it is heated and steamed with oxygen cut off. N ₂ is supplied as needed. The gas sucked from the furnace 24 passes through processes 25 such as exhaust gas combustion, gas cooling, etc., and is sucked into an exhaust blower 26, washed and discharged by a scrubber 27 and the like. The scrap car body supplied from the furnace 24 to the furnace 31 is a vacuum pump 3
At 3, the atmospheric gas is sucked, N ₂ gas is supplied if necessary, and Zn is recovered by the Zn recovery device 32. Furnace 3
4 and supply a reducing gas such as hydrogen to the supply port 37 if necessary.
From the vacuum pump 36 and the Zn recovery unit 35.
Collect. Next, while being cooled in the furnace 41, the atmospheric gas is sucked by the vacuum pump 42, and the collected scrap car body 43 is collected.
Is directed to the destination 44.

FIG. 3 is a flow sheet of another embodiment.
Reference numerals 1 to 13 are the same as in FIG. 5 scrapped bodies
Steaming is performed at a temperature of 00 ° C to 650 ° C and in a state where oxygen is cut off, and combustible components such as waste plastics, rubber, and fibers in the end-of-life vehicle are separated into pyrolysis gas, pyrolysis oil, moisture, and pyrolysis residue. The scrap car body containing the pyrolysis residue is further at a temperature of 500 ° C to 900 ° C and 10 ^-1 to 10 ^-3 Torr.
Hold for 30 to 120 minutes under reduced pressure of r.

The generated pyrolysis gas, oil and moisture are recovered as fuel after predetermined treatment such as acid and alkali cleaning after cracking, or are subjected to secondary combustion and used for heat recovery, that is, power generation. The scrap car body containing the pyrolysis residue decomposes dioxin in the high vacuum processing step 14 and removes heavy metals 15
Is collected, and the process is completed through a vacuum cooling step 16.

FIG. 4 is a schematic plan view of another processing apparatus of the present invention. Reference numerals 21 to 45 are the same as those in FIG. Furnace 5
Vacuum pumps 53, 63, 73 at 1, 61, 71, respectively
And the heavy metals are collected by the collecting devices 52, 62 and 72. In the embodiment, the first chamber (furnace 51): 350-500 ° C., the second chamber (furnace 6) under a reduced pressure of 10 ⁻¹ to 10 ⁻³ Torr.
1): up to 900 ° C., third chamber (furnace 71): heated to up to 1200 ° C., each of which was kept for 60 minutes.

Residues after heating in vacuum (non-evaporable metals,
Heavy metals (Cd, Pb,
Zn) and harmful substances (dioxins) are 0.00
%, And all were Tr (not detected) as a result of the dissolution test.

[0024]

According to the present invention, the waste car body is steamed and then heat-treated under reduced pressure, so that dioxin contained in the pyrolysis residue is dechlorinated and made harmless. In addition, heavy metals contained in the residue or used in plating or the like in end-of-life vehicles volatilize and are collected in an exhaust gas system, and the heavy metals can be recovered as valuable resources. There is also an effect that the iron plate whose surface has been oxidized during steaming is reduced by heat treatment under reduced pressure. Since the heavy metals have been sufficiently removed, the residue does not need to be landfilled in a controlled manner, and stable landfill disposal has become possible.

Next, the scrap remaining finally can be used as a raw material for steel, and the pyrolysis residue contains a large amount of pyrolytic carbon, so that it can be used as a carburizing material in an electric furnace or the like.

[Brief description of the drawings]

FIG. 1 is a flow sheet according to an embodiment of the present invention.

FIG. 2 is a schematic plan view illustrating a device configuration according to an embodiment of the present invention.

FIG. 3 is a flow sheet of another embodiment of the present invention.

FIG. 4 is a schematic plan view showing a device configuration of another embodiment of the present invention.

[Explanation of symbols]

 Reference Signs List 1 end-of-life vehicle (end-of-life vehicle) 2 removal of valuable parts 3 valuable parts 4 end-of-life vehicle 5 steaming 6 pyrolysis gas, oil, water 9 vacuum heat treatment 10 decomposition dioxin, heavy metal 11 scrap, pyrolysis carbon 12 cleaning treatment 13 fuel 14 vacuum heat treatment 15 Decomposition dioxin, heavy metal 16 Vacuum cooling 21 End-of-life vehicle body 22 Furnace 23 Vacuum pump 24 Furnace 25 Exhaust gas combustion, Gas cooling 26 Exhaust blower 27 Scrubber 31 Furnace 32 Zn recovery device 33 Vacuum pump 34 Furnace 35 Zn recovery device 36 Vacuum pump 37 Vacuum pump 41 Furnace 42 Vacuum pump 43 End-of-life vehicle body 44 Traveling direction 45 Pipe line 51 Furnace 52 Heavy metal recovery device 53 Vacuum pump 61 Furnace 62 Heavy metal recovery device 63 Vacuum pump 71 Furnace 72 Heavy metal recovery device 73 Vacuum pump

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroyuki Yamamoto 2-3-2 Uchisaiwaicho, Chiyoda-ku, Tokyo Kawasaki Steel Corporation (72) Inventor Hikaru Shimada 2-3-2 Uchisaiwaicho, Chiyoda-ku, Tokyo (72) Inventor Noboru Yasukawa 2-3-2 Uchisaiwaicho, Chiyoda-ku, Tokyo Kawasaki Ironworks Co., Ltd. (72) Sumio Yamada 2-3-2 Uchisaiwaicho, Chiyoda-ku, Tokyo Kawasaki Steel Inside (72) Inventor Masumi Hamada 2-5-1 Kitaaoyama, Minato-ku, Tokyo ITOCHU Corporation Inside (72) Inventor Yoshiaki Yokoyama 891-1 Minamiyajima, Ota, Gunma Prefecture Inside Ogihara Ecology Co., Ltd.

Claims (6)

[Claims] 1. A waste vehicle body obtained by removing valuable parts from a waste vehicle is steamed and separated into a pyrolysis gas, a pyrolysis oil, a waste vehicle body metal and a pyrolysis residue, and the waste vehicle body metal and the pyrolysis residue are kept at a high temperature. End-of-life vehicles that are introduced into a vacuum atmosphere and continuously heat-treated, and the decomposition products and evaporation in the pyrolysis residues are collected in a vacuum exhaust system, and after cooling, copper wires are removed from the metal of the end-of-life vehicle body. Thermal decomposition method. 2. A thermal cracking process for scrap according to claim 1, wherein the encapsulating the H ₂ gas during the heat treatment under the vacuum. 3. A heating furnace for housing a scrapped vehicle body for heat treatment, an N ₂ gas supply device disposed near an entrance and exit of the heating furnace, a vacuum heating furnace provided downstream of the heating furnace, and a vacuum pump. And a heavy metal recovery device. 4. A scrap car body is charged into a closed furnace, and once
After replacing the inside of the furnace with N ₂ gas, the closed furnace pressure was set to 765 Torr.
While maintaining the above conditions, the mixture is heated to 500 ° C. or more in an oxygen-free atmosphere, and then heated to a predetermined temperature under a reduced pressure of 10 ⁻¹ to 10 ⁻³ Torr to decompose harmful substances in the pyrolysis residue and heavy metals A thermal decomposition treatment method for end-of-life vehicles, comprising sequentially performing evaporative separation of the waste car. 5. The method according to claim 4, wherein the heating after the N ₂ gas replacement is performed to 650 ° C. or less by direct heating. 6. A heating furnace for storing and heating a scrap car body,
An N ₂ gas supply device disposed near the entrance and exit of the heating furnace;
A vacuum pump is provided downstream of the heating furnace, and includes a vacuum pump and compartment vacuum chambers provided with heating devices for increasing the temperature to the temperature required for evaporating heavy metals in the atmosphere thereof. A waste car pyrolysis treatment device, which is provided with a recovery device.